RE: [EXT] Re: [PATCHv11 00/10] block write streams with nvme fdp

[Pierre Labat <plabat@micron.com>]

Micron Confidential

Hi,

I was under the impression that passing write hints via fcntl() on any legacy filesystem stays. The hint is attached to the inode, and the fs simply picks it up from there when sending it down with write related to that inode.
Aka per file write hint.
I am right?

Pierre


Micron Confidential
> -----Original Message-----
> From: Christoph Hellwig <hch@lst.de>
> Sent: Monday, December 9, 2024 4:52 AM
> To: Keith Busch <kbusch@meta.com>
> Cc: axboe@kernel.dk; hch@lst.de; linux-block@vger.kernel.org; linux-
> nvme@lists.infradead.org; linux-fsdevel@vger.kernel.org; io-
> uring@vger.kernel.org; sagi@grimberg.me; asml.silence@gmail.com; Keith
> Busch <kbusch@kernel.org>
> Subject: [EXT] Re: [PATCHv11 00/10] block write streams with nvme fdp
>
> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments unless you
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>
> Note: I skipped back to this because v12 only had the log vs v11.
>
> On Thu, Dec 05, 2024 at 05:52:58PM -0800, Keith Busch wrote:
> >
> >  Not mixing write hints usage with write streams. This effectively
> > abandons any attempts to use the existing fcntl API for use with
> > filesystems in this series.
>
> That's not true as far as I can tell given that this is basically the architecture
> from my previous posting.  The block code still maps the rw hints into write
> streams, and file systems can do exactly the same.
> You just need to talk to the fs maintainers and convince them it's a good thing
> for their particular file system.  Especially for simple file systems that task
> should not be too hard, even if they might want to set a stream or two aside
> for fs usage.  Similarly a file system can implement the stream based API.
>